MINNEAPOLIS -- Minnesota Vikings tight end John Carlson seemingly has been invisible all season. On Thursday night, though, it probably won't be an illusion.

Carlson left Sunday's win over Arizona with what the team believes is a concussion, leaving him a long shot to make the short turnaround and play four days later against Tampa Bay.

"We'll have to go through some things in the next 48 hours to see where he is," coach Leslie Frazier said.

Barring a remarkable recovery for Carlson, there's a strong chance the Vikings will re-sign Allen Reisner off their practice squad.

Reisner, 24, appeared in the first three games this season on special teams, then was waived on Sept. 27 to make room on the 53-man roster for receiver Jerome Simpson, who had been suspended.

Kyle Rudolph plays almost every snap and the Vikings also have rookie fourth-round draft pick Rhett Ellison, but offensive coordinator Bill Musgrave uses two- and three-tight end sets liberally and likely would want another body available.

Carlson, 28, signed a five-year, $25 million contract with the Vikings in March that included $9.1 million in guarantees. They hoped he'd provide a 1-2 tight end threat along with Kyle Rudolph after missing last season in Seattle with a shoulder injury.

But Carlson sprained a knee the first week of camp, missed the entire preseason and has struggled to get regular work. He entered Sunday's game with just three catches for 8 yards and wasn't targeted before departing in the second half.

This isn't Carlson's first concussion. He was hospitalized overnight in Chicago in January 2011 after suffering a concussion in the Seahawks' playoff loss to the Bears. That reportedly was the third documented concussion of his career, dating to his days at Notre Dame.